Component operating on acoustic waves

ABSTRACT

A component operating with acoustic waves is described herein. The component includes a substrate having an underside subdivided into a center area and an edge area surrounding the center area on all sides. The component also includes a plurality of outer terminals in the edge area, and a plurality of inner terminals in the center area comprising at least a first inner terminal configured as a signal terminal.

CROSS REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 USC §120, this application claims the benefit ofPCT/DE2006/002014 filed Nov. 16, 2006 which claims the benefit of GermanPatent Application No. 102005056340.6 filed Nov. 25, 2005. Each of theseapplications is incorporated by reference in its entirety.

BACKGROUND

Components operating with acoustic waves are known for instance from thepublication U.S. Pat. No. 6,791,437 B2.

SUMMARY

A problem to be solved is to specify a component with a low crosstalkbetween two signal paths to be separated from one another.

According to a first preferred embodiment, a component operating withacoustic waves is specified comprising a substrate, the underside ofwhich is divided into an edge area and a center area surrounded on allsides by the latter. Outer terminals are arranged in the edge area andan arrangement of inner terminals is arranged in the center area. Thearrangement of inner terminals comprises at least one first innerterminal, which is provided as a signal terminal.

The terminals of the component are also referred to as pins or solderpads. Terminals that are arranged in two mutually perpendicularpreferred directions between two other terminals of the pattern ofterminals, known as a footprint, are referred to as inner terminals. Thepreferred directions are, for example, defined parallel to the edges ofthe substrate's underside. Those terminals which are arranged in theedge area of the substrate underside (or outside the center area) arereferred to as outer terminals.

In one variant, the arrangement of inner terminals has at least onesecond inner terminal which is provided as a ground terminal. A (firstor second) inner terminal is positioned such that that it lies in eachof two mutually perpendicular directions between two other terminals,e.g., between two outer terminals.

The substrate is, for example, a multilayer substrate with metallizationplanes, between which dielectric layers are arranged. The substrate isan LTCC substrate, for example. A chip having components operating withsurface acoustic waves and/or bulk acoustic waves is preferably mountedon the substrate.

In one variant, a duplexer circuit that comprises a transmit filter anda receive filter is in the component. These filters have acousticresonators that are arranged in the chip or on the chip, for example.The filters are electrically connected to the inner and the outerterminals of the component via electrical connections integrated intothe substrate. The duplexer circuit can have an antenna-side matchingnetwork, e.g., a transmission line arranged in the receive path. Thismatching network is preferably integrated into the substrate, with itsLC elements or line segments being realized, for instance, by conductortracks or conductor areas arranged in the metallization planes.

According to the second preferred embodiment, a component operating withacoustic waves is specified, comprising a substrate, on the underside ofwhich first signal terminals and second signal terminals are arranged.The center points of the at least two second signal terminals liesubstantially on an imaginary center line that runs in the centerbetween two first signal terminals.

The first signal terminals are preferably assigned to a balanced portthat is connected, for example, to a receive path with symmetricalsignaling. The second terminals are preferably each assigned to asingle-ended port.

In one variant, the component comprises a duplexer with an antennaterminal, a transmit input and a receive output. The receive output ispreferably assigned to the balanced port. One of the second signalterminals is provided as an antenna terminal, the other second signalterminal being assigned to the transmit input.

The arrangement of the antenna terminal between the signal terminal ofthe transmit path and the signal terminals of the receive path isconsidered advantageous.

A first ground terminal can be arranged between the antenna terminal andthe signal terminal of the transmit input. A second ground terminal canbe arranged between the antenna terminal and the signal terminals of thereceive output. Preferably each of these ground terminals has a largersurface area than the first and second signal terminals. Additionalinner or outer ground terminals can also be provided, preferably alsohaving a larger surface area than the signal terminals. Additionalsignal terminals can also be present.

In one variant, the terminals comprise two successive terminals withdifferent surface areas, wherein the terminal with a smaller surfacearea is provided as a signal terminal, and the terminal with the largersurface area is provided as a ground terminal. The terminals comprisefor example, at least two successive terminals with differing widths,wherein the terminal with the smaller width is provided as a signalterminal and the terminal with the greater width is provided as a groundterminal.

According to the second preferred embodiment, a component operating withacoustic waves is specified, comprising a substrate, the underside ofwhich comprises at least three terminals arranged one alongside theother in a preferred direction, wherein at least two of these terminalshave widths differing from one another relative to the preferreddirection. The ratio of the differing widths lies between 1 and 2 in anadvantageous variant, but can in principle also be greater than two.

A grounding surface, which is arranged in the substrate and is providedfor shielding the circuit elements integrated into the substrate (inparticular, the matching network of the duplexer), can be connected to aground terminal. A grounding surface, for example arranged on the rearside of the chip that is provided for shielding the component structuresintegrated in the chip can also be connected to a ground terminal.

The terminal with the smaller surface area or width can be provided inall preferred embodiments of the component as a signal terminal, and theterminal with the larger surface area can be provided as a groundterminal. It is advantageous to select an average size of the terminalsprovided as signal terminals to be smaller than an average size of theterminals provided as ground terminals.

The terminals arranged on the underside of the component can be suitablefor surface mounting in all preferred embodiments.

In all preferred embodiments of the component, the underside of thecarrier substrate can comprise an arrangement of terminals arranged onealongside the other in one direction, wherein the distances betweensuccessive terminals can differ from one another. It is provided that,in particular, relative to at least one preferred direction, thedistance between a signal terminal and the adjacent terminals (groundterminals or at least one additional signal terminal) is selected to begreater than the distance between two ground terminals arranged onealongside the other relative to a preferred direction.

The arrangement of terminals arranged one alongside the other in apreferred direction can optionally have terminals that are offset withrespect to one another perpendicular to the preferred direction, so thattheir centers do not lie on one line. It is also possible, however, forthe terminals of this arrangement to form a row, wherein their centersor edges (e.g., edges facing inward or outward with respect to thecenter of the substrate) lie on an imaginary line.

DESCRIPTION OF THE DRAWINGS

The specified component will be described below on the basis ofschematic figures not drawn to scale.

FIG. 1 shows the plan view onto the underside of the component, and itssubdivision into an edge area and a center area;

FIG. 2, an example of a footprint with a pin matrix having innerterminals;

FIG. 3, a component in cross section with an acoustic chip that ismounted on a carrier substrate, on the underside of which innerterminals are provided;

FIG. 4, a circuit with a duplexer realized in the component according toFIGS. 2, 3.

DETAILED DESCRIPTION

FIG. 1 shows an imaginary subdivision of the underside of a carriersubstrate TS, shown in FIG. 3 for instance, with an edge area RB and acenter area MB. Edge area RB is an area having the shape of a frame thatfaces the outer edges of the carrier substrate. Edge area RB is an areathat is free of inner terminals IA1, IA2. On the other hand, the centerarea is an area that is free of outer terminals AA. Terminals AA, IA1and IA2 are SMD terminals.

FIG. 2 shows the footprint (terminal arrangement) of a componentoperating with acoustic waves in which a duplexer circuit is realized.The footprint is realized in the lowermost metallization plane ofsubstrate TS.

Outer terminals AA are arranged in edge area RB, and a first innerterminal IA1 and several second inner terminals IA2 are arranged incenter area MB. The ratio of the widths of the center area and the edgearea can in principle be arbitrary. The width of the edge area issubstantially determined by the length of the outer terminals AA, or thelongest of these terminals. The connecting points between terminals IA1,IA2 and contact areas, not shown in the figures, of an external circuitboard can be solder pads or bumps, for example.

Terminal IA1 is a signal terminal and terminals IA2 are groundterminals. Terminal IA1 in this case is an antenna terminal ANT. Allterminals form a footprint in the form of a pin matrix that has severalrows and five columns.

Successive terminals in the horizontal direction form a row andsuccessive terminals in the vertical direction form a column. Forexample, the successive terminals GND, GND1, GND6 and GND2 form one rowand the terminals TX, GND1, ANT and GND2 form an additional row.Terminals GND1, GND2 and RX1 follow one another in a horizontaldirection and therefore form a row. In principle the columns can beinterchanged with the rows in case of a rotation of the footprint by90°, for example.

The first ground terminal GND 1 serves to shield antenna terminal ANTfrom the unbalanced-to-ground transmit input, which has a signalterminal TX. The second ground terminal GND2 serves to shield antennaterminal ANT from the ground-symmetric receive output, which has twosignal terminals RX1, RX2.

Additional ground terminals, including terminals GND3, GND4, GND5, areprovided. Apart from the signal terminals RX1, RX2, TX and ANT, allother terminals are preferably connected to ground. The surface area ofthe signal terminals RX1, RX2, TX and ANT is smaller than the surfacearea of the ground terminals. It is possible for example, to select thewidth L1 of signal terminal TX, measured in the vertical direction, tobe smaller than the width L2 measured in this direction of the groundterminals GND, GND3 adjacent to this signal terminal.

The distance between signal terminal TX and the adjacent terminals GND,GND1, GND3 is preferably larger than the distance between two groundterminals, e.g., between terminals GND and GND1 or GND4 and GND5. Thisalso applies to the signal terminals ANT, RX1 and RX2.

The surface area of the ground terminals GND1, GND2 provided between twohot terminals is selected to be greater than the surface area of otherground terminals, which serve, for instance, for ground contact with aground contact area in substrate TS.

The dimensioning and positioning of the terminals of a footprintexplained in connection with FIG. 2, in particular, the relativedimensioning and positioning of the signal and ground terminals,represent measures according to the third preferred embodiment of thecomponent.

The footprint shown in FIG. 2 has, according to the second preferredembodiment of the component, first signal terminals 11, 12 and secondsignal terminals 21, 22. The center points of second signal terminals21, 22 lie on an imaginary center line ML that runs in the middlebetween two first signal terminals 11, 12.

The first terminals are preferably equally large and aremirror-symmetrically arranged relative to line ML, which runs throughthe centers of second terminals 21, 22. Thus the same distance of thetwo first terminals 11, 12 from terminal 21 and from terminal 22 isguaranteed.

First terminals 11, 12 in the variant according to FIG. 2 are signalterminals RX1, RX2 of a first ground-symmetric receive output. Secondterminal 21 is a signal terminal TX of an unbalanced-to-ground transmitinput. The additional second terminal 22 is an antenna terminal ANT,thus also a signal terminal of an unbalanced-to-ground electric port.

FIG. 3 shows an example of a component in cross section. The componentcomprises a substrate TS and a chip CH arranged thereon which comprisescomponent structures operating with acoustic waves.

Substrate TS comprises several dielectric layers, e.g., LTCC layers. Thedielectric layers of the substrate are arranged between metallizationplanes. The metallization planes are conductively connected to oneanother by means of plated through-holes. The metallization planescomprise circuit elements such as inductors, capacitors, or transmissionlines, including the transmission line TL shown in FIG. 4.

The outer and inner terminals AA, IA1, IA2 of the component, which werealready shown in FIG. 2, are formed in the lowest metallization plane ofcarrier substrate TS. In its uppermost metallization plane, contactareas are formed which can be connected to the terminal areas of chip CHby means of bumps in a flip chip arrangement of chip CH. The electricalconnection between the contact areas of carrier substrate TS and theterminal areas of chip CH is alternatively possible by means of bondwires, in case the rear side of the chip faces towards the carriersubstrate.

FIG. 4 shows a front end circuit with a signal path that comprises anantenna path (transmit-receive path) connected to an antenna terminalANT, a transmit path connected to a transmit input TX and a receive pathconnected to a receive output RX1, RX2.

Duplexer DU comprises a transmit filter F1 arranged in the transmitpath, a receive filter F2 arranged in receive path RX, and a matchingnetwork that can comprise a transmission line TL arranged in the receivepath.

Transmission line TL preferably has a quarter wavelength at the transmitfrequency associated with the signal path. A λ/4 line emulated by LCelements can be used in place of transmission line TL. These LC elementsare preferably integrated in substrate TS. Alternatively the matchingnetwork can also have, for instance, a parallel inductor and a seriescapacitor.

The filters F1, F2 associated with duplexer DU each comprise BAWresonators and/or at least one SAW transducer. The resonators ortransducers can be interconnected in a ladder-type arrangement, forexample.

A balun is integrated in receive filter F2 in the variant shown in FIG.4. It is also possible to connect a balun, which is preferablyintegrated in substrate TS, on the output side of receive filter F2 witha single-ended output.

Different measures explained above for designing a footprint can bearbitrarily combined with one another.

1. A component operating with acoustic waves, comprising: a substratecomprising: a first pair of signal terminals associated with a balancedport; and a second pair of signal terminals on an underside of thesubstrate, the second pair of signal terminals being assigned to asingle-ended port; wherein centers of the signal terminals of the secondpair of signal terminals are on a center line between the signalterminals of the first pair of signal terminals.
 2. The component ofclaim 1, further comprising: a duplexer having an antenna terminal, atransmit input, and a receive output; wherein the receive output isassociated with the balanced port; and wherein the second pair of signalterminals comprise a first terminal and a second terminal, the firstterminal being configured as the antenna terminal and the secondterminal being associated with the transmit input.
 3. The component ofclaim 2, wherein the antenna terminal is between a signal terminal ofthe transmit input and signal terminals of the receive output.
 4. Thecomponent of claim 3, further comprising: a first ground terminalbetween the antenna terminal and the signal terminal of the transmitinput; and a second ground terminal between the antenna terminal and thesignal terminals of the receive output.
 5. The component of claim 4,wherein the first and the second ground terminals have a first surfacearea; and wherein the signal terminals of the first pair of signalterminals and the signal terminals of the second pair of signalterminals have a second surface area, the first surface area beinglarger than the second surface area.
 6. A component operating withacoustic waves, comprising: a substrate having an underside subdividedinto a center area and an edge area surrounding the center area on allsides, a plurality of outer terminals in the edge area; a plurality ofinner terminals in the center area comprising at least a first innerterminal configured as a signal terminal; and a plurality of ground andsignal terminals configured one alongside the other in one directionhaving a varying distance between successive terminals; wherein adistance between at least one of the signal terminals and each of aplurality of terminals adjacent to the at least one of the signalterminals is selected to be larger than the distance between twoadjacent ground terminals.
 7. The component of claim 6, wherein theplurality of inner terminals comprise at least a second inner terminalconfigured as a ground terminal.
 8. The component of claim 7, whereinthe plurality of outer and inner terminals on the underside of thesubstrate form a pin matrix; and wherein the first and the second innerterminals are in each of two mutually perpendicular directions betweentwo other terminals of the pin matrix.
 9. The component of claim 6,further comprising: a chip mounted on the substrate having componentstructures and operating with surface acoustic waves.
 10. The componentof claim 9, further comprising: a duplexer circuit having a transmitfilter and a receive filter; wherein the transmit filter and the receivefilter are in the chip or on the chip, and connected to at least some ofthe plurality of outer and inner terminals via electrical connectionsintegrated in the substrate.
 11. The component of claim 6, furthercomprising: a chip mounted on the substrate having component structuresand operating with bulk acoustic waves.
 12. The component of claim 11,further comprising: a duplexer circuit having a transmit filter and areceive filter; wherein the transmit filter and the receive filter arein the chip or on the chip, and connected to the plurality of outer andinner terminals of the component via electrical connections integratedin the substrate.
 13. The component of claim 6, wherein the plurality ofouter and inner terminals comprise at least two successive first andsecond terminals with different widths; and wherein the first terminalis configured as a signal terminal and has a first width, and the secondterminal is configured as a ground terminal and has a second width, thefirst width being smaller than the second width.
 14. The component ofclaim 6, wherein the plurality of outer and inner terminals comprise atleast two successive first and second terminals with different surfaceareas; and wherein the first terminal is configured as a signal terminaland has a first surface area, and the second terminal configured as aground terminal has a second surface area, the first surface area beingsmaller than the second surface area.
 15. The component of claim 6,wherein the plurality of outer and inner terminals on the underside aresuitable for surface mounting.
 16. The component of claim 6, wherein theplurality of outer and inner terminals are configured as signalterminals and have a first average size; and wherein the plurality ofouter and inner terminals are configured as ground terminals and have asecond average size, the first average size being smaller than thesecond average size.
 17. A component operating with acoustic waves,comprising: a substrate having an underside subdivided into a centerarea and an edge area surrounding the center area on all sides, aplurality of outer terminals in the edge area; a plurality of innerterminals in the center area comprising at least a first inner terminalconfigured as a signal terminal; and a plurality of ground and signalterminals configured one alongside the other in one direction having avarying distance between successive terminals; wherein: a distancebetween at least one of the signal terminals and an adjacent terminal isselected to be larger than the distance between two adjacent groundterminals; the plurality of outer and inner terminals comprise at leasttwo successive first and second terminals with different surface areas;and the first terminal is configured as a signal terminal and has afirst surface area, and the second terminal configured as a groundterminal has a second surface area, the first surface area being smallerthan the second surface area.